1. Field of the Invention
The present invention relates to the field of sound reproduction, more specifically to the field of sound reproduction using an earphone.
2. Description of Related Art
The use of headphones for sound reproduction is known. Typically, high fidelity headphones are large, bulky devices that have a first speaker enclosure, a second speaker enclosure, and a “C” shaped band that connects the two speaker enclosures and holds the enclosures against the user's ears. While functional, these devices tend to be heavy and uncomfortable and, if the user is moving in a vigorous manner, overly warm on the users ears. Furthermore, traveling with these devices can be difficult due to the size of the headphones and the space it takes to store them.
As the speaker enclosures are held against the individual's ears, and as an ear is not typically a smooth surface against which the enclosures can readily be sealed, headphones suffer from unwanted exterior sound interfering with the listener's ability to enjoy the reproduction of sound. Attempts to solve this problem have used compressible sealing elements to improve the seal between the user's ears and the enclosure or to use active noise cancellation techniques to cancel out exterior noise.
To reduce the bulkiness and weight, in-the-ear speakers or earphones have been designed to replace headphones. The advantage of earphones over headphones includes a substantial reduction in size and weight, less trapping of the user's heat, and the potential for a significant reduction in unwanted external noise without the need for active noise reduction as is found on some headphone models.
Earphones, however, have certain design challenges. The small space available requires the use of smaller drivers and careful internal acoustic sealing to ensure the sound is directed to the user's ear. In addition, the exterior of the earphone must also be suitable for sealing the exterior of the earphone to the user's ear if the desired sound isolation is to be provided. Furthermore, the small size of the driver makes the production of lower frequencies more difficult. One method of providing a full range of sound reproduction, such as is used in the Shure® E5c earphone, is to use a smaller and a larger driver in combination. While such a design is well suited to reproducing sound with a high degree of fidelity, using two drivers tends to make an earphone somewhat larger in size and more costly to produce. Thus, it would be desirable to provide an earphone that can provide a desired range of frequency response without the need to use two drivers so that the cost of manufacturing the earphone can be reduced.
In addition, as earphones typically have a nozzle that is inserted into the user's ear, the accumulation of cerumen or earwax can be a problem. This problem could be particularly acute if the user is, for example, a performer using the earphones as a monitor with a Shure® PSM 600 in a wireless mode. The lack of wires allows the performer to move about in a more spontaneous and vigorous manner. Thus, the performer is not limited to performing in front of a traditional monitor and this gives the performer greater freedom to move. However, vigorous movement of a performer can generate body heat and body heat can cause the wax in the performer's ear to liquefy such that it will enter the earphone nozzle. The liquefied earwax can thus leave deposits on a filter inside the nozzle. Over time, these deposits can prevent the earphones from working as intended, either by reducing the sound output levels or by changing the tonal quality of the sound being produced, or both. It would be desirable to provide a way for the user to readily resolve this issue without complicated or difficult disassembly and reassembly of the earphone.
Another issue is that different individuals have different preferences regarding how bright or warm the music should be when reproduced. Some of the variance can be accounted for by the individual variance in hearing. However, some portion of the difference rests with the individuals' perception of what the reproduced sound should sound like and/or the type of music typically being reproduced for the individual. Thus, it is recognized that some individuals prefer a warmer sound and some individuals prefer a brighter sound. It would be desirable to provide a means for allowing a user to readily customize an earphone so that the sound reproduction fit the user's musical tastes and hearing ability.
It should be noted that, as is known, brightness and warmth generally refers to the perception of reproduced sound, with brightness being related to higher frequencies such as the band between about 4 and 10 kHz and warmth being related to lower frequencies such as the band between about 150 and 500 Hz. Thus, as used herein, the brightness or warmth of reproduced sound corresponds to the amplification or attenuation of different portions of the frequency response.